Display shows F4; door opens but will not close from remote; wall button may still close the door with constant pressure.

Safety first: Never bypass the safety beams permanently.

• Step 1 – Observe beam LEDs: Watch the LEDs on the B&D safety beams while gently tapping the brackets and wiggling the wires. If the LEDs flicker, improve alignment and secure wiring.
• Step 2 – Replace beam pair: If alignment and wiring are good but F4 persists, replace both the transmitter and receiver beams as a matched B&D kit.
• Step 3 – Route wiring away from mains: Keep beam wires away from high‑voltage cables to reduce electrical noise.
• Step 4 – Reset opener: After beam replacement, power cycle the opener and test close commands from both remote and wall button.